Mechanical recording



Patented .my 14, 193s lwir-swr OFFICE i' A 2.04m csnn'aoonpma y @u nur', Netherlands,

assignortoN.V.Philips abrleken, EindhovcmNetherlands -InGermany This invention relates to the mechanical recording of optically reproducible vibration tracks and to the carriers used for such tracks. and more Vparticularly to the recording of sound vibrations on a carrier, which is preferably a film.

In the known methods of .this type of recording the vibration track is produced by removing from .a substratum, in accordance withfthe vibrations to be recorded.- parts of a covering layer, sometimes withthe removal of portions of the sub- Y stratum, itself, so' that a-vibration track having width variations, and sometimes also depth variations, is `formed. of opaque material and the substratum of vtransparent material, or when using t material for boththe covering layer and substratum. by subsequently blackening either thetrack, surface or the background constituted by the covering layer, the record soi'ormed can be optically reproduced .by meansof aphoto-lectric cell. or 'photographic prints can be made thereof. To reinforce the carrier, especially in the case of a film, the layer and the substratum are usually applied to a strong base layer madefof transparent material, for example ofv celluloid. In a modincation oi the said known methods the record is produced on a carrier of which the part intended forthe record comprises v.tvvo adjoining transparent layers one of which is constituted by amaterial to rwhich a vdyestuir readib adheres, 'the'second layer, which preferably is the coveringlayer, being oi' a material to which the dyestui does not adhere., the base layer, if present, being made of an also nt material.

The term dyestui!" as used herein is intended to include all those substances' (dyes. inks. etc), which are capable of bringingabout, for the optical reproduction of the record, the desired diierence in transparency of the vibration track and of its background and/or which may serve as a printing color.

By the expression "reproduction" as used herein, is meant both a direct reproduction of the vi- 45 bration track, by means o! aphoto-electric cell,

as well as its photographic copying. l

By making the covering layer and the substratum of materials as described, reproduction can be eiected in several dierent ways, depend- 50 Y ing upon conditions and purpose.n

For instance, by treating with a suitable dyestuft the mechanically-recorded record. that is either the vibration `track itself cr its background, duplicates thereof'can be obtained either optib cally, 4or mechanically by means ot one of thewell- By making the covering'layer known printing methods, and without requiring Special measures, subsequent to the recording, to

Vprevent dyestuil'irom adhering at such portions of the'record where it is not desired.

According to the present invention, the covers.

vaoco-ccoo A) Just as other layers.' which the carrier maybe Thelatterbeingv moreover transparent tofini'ra-edA-,rays inl this case. The symbol as used'above represents 15 Angstmm units, i. e. a unit or length tc one ten-thousandth of a micron, or 10centi meters. Ir now the covering layer is made of a dyestuiT-repelling material and the cutting or intermediate layer is made of almaterial which has gu'V dyestufi'fretaining properties and which is transparent to red and infra-red rays. whereas the base layer, which is usually made of. celluloid. is

also transparent to red and infra-'red rays, there are various possibilities. z5 The direct reproduction ot the record immef* diately after it has been'vrecorded (play-back) by means of a photocell, a light source, occasionally combined with a suitable illter, producing only red andr infra-red rays. and the usual optical or s0 light-slit, requires no treatment of the record with a dyestuif. As the maximum'sensitivity of present-day photocells is in the-red and infrared range. the red-opaqueness of the background is suiiicient to obtain its desired contrast with 35 the track.

However, i'or the printing of copies from the record, light having its greatest actinism within the range or 3.000 A tc 4,000 A, is used. when both the covering layer and the intermediate layer (and also the base layer) are transparent to such rays, before making prints of the record, the track is rendered opaque to such light by a suitable 'dyestuil' which, however, does not need to be a printing color.

Most dyestuns are suitable for this pln'poe, the only claim to be fuiilled being that it is opaque' f to violet and ultra-violet light rays. For instance nigrosine may be used.

A special advantage can be obtained, if a dye stui! is chosen. which besides being opaque to violet and ultra-violet rays is moreover transparent to red and infra-red rays. In this ease the original track remains readily reproducible. es

can be obtained duringthe recording, copyingor` reproduction, if measures are taken to so limit the transparent portions of the record that the reproduction is subjected .only to the inuence of the amplitude variations and not to that of the particles of dirt or scratches present at the transparent portions.

If the original sound-record is "noiseless" the edges quite small movements of the cutting tool 15 reproduction of the original record or of a copy thereof is noiseless, if only the track itself transmits the light during reproduction.`

Furthermore it is proposed to obtain the contrast in the adhering properties of the two layers by forming one layer of tanned gelatin and the other of untanned gelatin. If tanned gelatin is treated with water it adheres fatty colors, but in the contrary repels aqueous colors. Untanned gelatin has just the reversed properties. I t repels fatty colors, but adheres aqueous colors.

Several possibilities for mechanical printing are present now:

Example 1.-The tanned gelatin and the layer is formed of untanned gelatin:

A. For printing a fatty color isused: a. print is 'covering layer is formed of obtained, which is readily reproducible.

B. For printing an aqueous color is used: :a diapositive is obtained from which by opt'cal reprinting readily reproducible prints can be obtained.

Example 2.--The covering layer is formed of untanned gelatin, whereas the intermediate -or cutting layer is formed of tanned gelatin:

A. For printinga fatty color is used: a diapositive is obtained from which by optical reprinting readily reproducible prints can be made.

B. For printing an aqueous color is used: a print is obtained which is readily reproducible. It will be clear of course that the above mentionedcarriers treated with a dyestufl' can be also used for photographic prints. The same number of possibilities are presentand it is superfluous to recall them therefor.' They can be readily deducted from the mentioned examples by replacing B for A and A for B.

, In order that the invention may be more clearly understood and readily carried into effect, it will be more fully explained with reference to the accom drawing in which: I

Figure 1 is an enlarged cross-sectional elevation of a carrier according to the invention, including the cutting tool used for the recording.

Fig. 2 is a cross-sectional side view of Figure l. showing the vibration track as cut by the cutting tool.

Figs. 3, 4 and 5 are plan views of lms according to the invention. showing dierent modifications.

`which the vibration track Referring to Figs. 1 and 2, the carrier consists of a relatively sturdy base layer I, for instance of celluloid, of a substratum or cutting layer V3 into is cut, and ofy a thin covering layer 2 which is non-transparent to red and infra-red light rays and preferable transparent to violet and ultra-violet rays and which is removed at portions corresponding to the vibration track, The layers 2 and 3 may be either dyestun-retaining 'or dyestuif-repellent as fully set out above, but in everv case the subsequent layers 'must have opposite properties. The layers 3 and factory reproduction, that a minimum amplitudiintermediate or cutting duced by vmeans of a photocell, or, as is the usual.

aocaeeo d are both transparent to red and infra-red rays and preferably also transparent to violet and ultra-violet rays. v

A cutting tool I is. provided for recording the sound vibrations and is vibrated perpendicularly 5 to the surface of the carrier in agreement with the vibrations to be recorded.v As the amplitudes of vibrationl of the cutting tooly are very small at high frequencies, andas itis essential, for satisnal variation of the vibration track be obtained,

the cutter is provided with v-shaped cutting edges B, which form with each other an angle a `of about 174. Due tb such slope of the cutting are convertedinto large width variations of the vibration track being cut, and in addition to these rwidth variations, depth variations are also formed. yAllis a result of this, i trackl as shown for example in .record treated in this manner is suitable, with--I out additional means, for mechanical multiplica.-v tion by means of one ofthe well-known printing 30 methods. g v y If dye isl used instead of a special printing color, the record may be either optically repro` case, may be photographicallymultiplied, i. e.,- one or more photographic copies may be made. A record formed and treated in this manner has the additional advantage that when itis to be used for direct optical reproduction, it is possible to determine after the recording, which dyestuff 40 is best suited to obtain a coloring layer having the desired light absorption with regard. to the luminous rays used in reproduction.

When the covering layer 2 is made of dyestuffrepellent material and the cutting layer 3 is made of dyestuff-absorbing material, the can-ier, after being cut and treated with the dyestuff, appears'as shown in. Fig. 5, in which the colored portion (now corresponding to the vibration track) is indicated by cross-hatching. The depth kof the track is sufflciently small that the color or ink completely nils the track whereby duplicates of the record can be obtained by mechanical printing.

While the duplicates of such records obtained by printing are suitable for optical reproduction by means of a photo-electric cell, they have the drawback that because of the extent of the transparent portion it is difficult to avoid background noise, and therefore it is preferable to photographically duplicate the record so as to obtain 60 copies in which the track is transparent and the background is opaque.

If a vibration track as shown in Fig. 3 is recorded in a noiseless" manner on a carrier whose covering layer is opaque to red and infra-red rays, the record so formed may be immediately reproduced lin a noiseless manner by means of the usual photo-electric cell apparatus. ABy noiseless" recording is meant a method 'of recording. in which the central or neutral position of the 7 recording member, for instance the cutting tool, shown in Figs. l and 2, is changed during the recording in accordance with the amplitudes of 'the vibrations being recorded. For instance,

when the amplitudes of the vibrations being re- 75 corded are small, the central position of the above-mentioned cutting tool is raised, whereby th Width f the' track, and hence the Width 0I Y the transparent portion between the inwardly- 6 directed peaks of the boundary lines oi the-track. is reduced. IlBy using a covering layer opaque to red and infra-red ra the degree to which the record is free from noise can be determined immediately alter the recor l0 By subsequently treating this record with a ,estuiItoobtainarecordasshowninFig the record can be photographically copied. wherebyo'n the copies the track is free from the rustling noise usually present when reproducing l5 iilm of the t generally used. In addition.

of speciilc examples, and for speciilc applications,

I do not wish to be limited thereto, but desire the appended claims to be construed as broadly as permissible in view of the prior art. 30 what r claim is:

1. A' carrier for the mechanical 'recording of an optically-reproducible vibration track, com- 'prislng a covering layer of a material opaque to red yand infra-red rays, the remaining portion of 35- the carrier Abeing transparent to said rays, and a second layer beneath said covering layer, the material lof one of said layers being dyestuiI-retaining and the material oi the other layer being -repellent.' n

40 f 2. A carrier for the mechanical recording of an optically-reproducible vibration track, comprising'a covering layer of a material opaque to ,red and infra-red rays andl transparent to violet and ultra-violet rays. the remaining portion of 45 the can'ier being transparent to said rays, and

a second layer beneath said covering layer, the

` material of one of said layers being dyestulI-repellent and the material ofthe other layer being dyestu-retaining.

50 3. A carrier for the mechanical recording of `an optically-reproducible vibration track, comprising a covering layer oi a material opaque to red and infra-red rays. the remaining portion of the vcarrier being transparent to said rays, and a 55 second layer beneath said covering layer, one of said layers being of tanned gelatin and the other layer being of untanned gelatin.

4. In the manufacture of carriers for themeo ychanical recording of an optically-reproducible vibration track, the process comprising the steps of forming a layer oi'a material opaque to red and infra-red rays, forming a second layer oi' a material transparent to red and infra-red rays, 65 the material of one layer being dyestu1l'repellent and the material of the other layer being dyestu-retaining, and conjoining said layers to form the carrier withsaidilrst layer on top. l

5. In the manufacture of carriersfor the me- 70 chanical recording of an optically-reproducible vibration track, the process comprising the steps; forming' a layer of a material opaque to red and intra-red rays and transparent to 'violet and ultra-violet rays forming a second layer of a ma- [5 terial transparent to .violet, ultra-violet, red and ,ing the steps:

infra-red rays. the materiall oi one layer being dyestuff-absorbent and the material of the other layers being dyestuiI-repellent; and conioining said layers with the rst layer on top. to form the carrier.

6. In the manufacture of carriers for the mechanical recording of an optically-reproducible vibration track, the process comprising the steps:

' forming a layer ola material opaque to red and infra-red rays; forming a second layer of a ma- 10 terial .transparent to red and infra-red rays, the

material of one layer being dyestuirepellent and the material of the other layer being dyestullretaining; and conjoining said layers together and to a base layer of a material transparent to l5 red and infra-red rays with the rst layer on top.

7. In the manufacture of carriers for the mechanical recording of an optically-reproducible vibration track, the process comprising the steps:

forming a layer of a material opaque to red and infra-red rays and transparent to violet and lultra-violet rays; forming a second layer of a material transparent to violet, ultra-violet, red and infra-red rays, the material of one layer being -dyestuirepellent and the material of the other 25 layer being dyestuiI-retaining; and conioining said layers together and to a base layer of a material .transparent to red, infra-red, violet and' ultra-violet rays with said iirst layer on top.

8. The method of mechanically recording an optically-reproducible vibration track, comprising the steps; -forming a layer of a material opaque to red and infra-red rays; forming a second layer` of a material transparent to red and infra-red rays, the material of one layer being dyestui-repellent and the material of the other layer being dyestuff-retaining; 'conjoining said layers together and to 4a, base layer of a material transparent to red and infra-redrays with said iirst layer on top to form a carrier; cutting a 40 vibration track into said ilrst two layers; and treating the carrier with a dyestuil to color only the dyestui-retaining material.

' 9. The method of mechanically recording an optically-reproducible vibration track, comprising the steps; forminga layer of material opaque to red and infra-red rays; forming a second layer oi.' `a material transparent to red and infra-red rays, the material of one layer being dyestuilretaining and the material of the other layer being dyestutf-repellenm uniting said layer together and to a base layer of a material' transparent to red and infra-red rays with said first layer on a top to form a carrier, cutting a vibration track into said rst two layers; and treating the carrier with a printing color adhering only to the dyestuit-retaining material.

10. 'Ihe method of mechanically recording optically-reproducible vibration tracks comprising the steps; forming a layer of a dyestuilrepellent material opaque to red and intra-red rays and transparent to violet and ultra-violet rays; forming a second layer of a dyestuiretain ing material transparent to red, infra-red, violet and ultra-violet rays; joining said layers together and to a base layer ofa material transparent to red, infra-red, violet 'and ultra-violet rays with said first layer on top to form a carrier; cutting a vibration track into said rst two layers; and treating the carrier with an opaque dyestuii' to 70 color only the dyestuietaining material.

l1. 'I'he method o f mechanically recording optically-reproducible vibration tracks. comprisforming a layer or a dyestuirrepellent material transparent to violet and ultraviolet rays and opaque to red'and infrared rays; forming a second. layer of va dyestuff-adherent material transparent to red', infra-red, violet and ultra-violet; uniting said layer together and to a base layer of a material transparent to red and infra-red rays withl said first layer on top to form a carrier; cutting a vibration track into said first two layers and treating the carrier to a nontransparent printing color adhering to only the' v dye'stui-adherent material.

12. The `method of mechanically recording optically-reproducible vibration tracks, comprising the; steps; forming a layer of a dycstuilbrepellent material transparent to' violet and ultraviolet rays and opaque to red and infra-red rays;` 'for-ming a second layer ofva dyestuiT-adherent material transparent to red, infra-red, violet and ultra-violet rays; conjoining said layers together and to a base layer olla material transparent to red and infra-red rays, with said iirst layer on top to form a carrier; cutting a vibration track I' into said rst two layers; and treating the carrier with a non-transparent printing color adhering 4only to the dyestuff-adherent material.

-13. The method of i mechanically recording optically-reproducible vibration tracks, comprising the steps; forming a base layer ot a material transparentgtored and infra-red rays; joining to one'side of said Ibase layer a cutting layer of a i dyestui-adherent material transparent, to red,

infra-red, violet and ultra-violet rays; joining to v the. free side oi' saldi cutting layer a covering layer of a dyestufbrepellent material transparent to violet and ultra-violet rays and opaque to red 'and infra-red rays; cutting a vibration track into said covering and cutting layers; and treating terial.

the carrier with adyestu,r transparent to only red and intra-red rays to color only the dyestuiadherent material.

14. The methodfoi mechanically recording l optically-reproducible vibration tracks', compris- 5 ing the steps; forming a ,base layer of a material transparent to red, infra-red, violet and ultra# vviolet rays; joining to one sideof said base layer a cutting layer of dyestui-adherent material transparent to red, infra-red, violet and ultra-- violet rays; `joining to the free side of vsaid cutting layer a covering layer of a dyestufI-repellent material transparent to violet and ultra-violet rays, and opaque to red and infraeredrays; cutting a vibration track into said cutting and covering layers; and treating the carrier with a printing color transparent to only red and infra-red rays and adhering to only the dyestufl-adherent ma- 15. In the reproduction. of mechanically-- recorded and optically-reproducible vibration tracks, the process comprising the steps; forming a layer of a dyestufi-retaining material transparent to ultra-violet and infra-red rays; superimposing on said layer -a covering layer o f adyestuff-repellentmaterial opaque to red and infrared rays and transparent to ultra-'violet rays:

mechanically recording a vibration track in saidy layers; reproducing said track by means of a photocell having a maximum sensitivity iorred 30.

and infra-red rays; ltreating the layers with an ultra-violet opaque dyestui which adheresonly to the track; and producing a copy by means of ultra-violet light. A

JAN n: Bonn. 

